clean up some SK_LEGACY... defines

Change-Id: I86c9f983672e6edd616afe003ea9823da7890511
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/290585
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
2 files changed